In general, a stent is an expandable medical prostheses and is used in body vessels of a person for various medical purposes.
Examples thereof include intravascular stents for treating stenoses, and stents for maintaining urinary, biliary, tracheobronchial, esophageal, and renal tracts, and an opening of inferior vena cava.
In general, the stent is transported to a treatment site through the body vessels by using a transporting device that maintains the stent in a contracted state.
In percutaneous transluminal angioplasty, implantable endoprosthesis, that is, the stent is introduced through the transporting device and transferred to the treatment site through vessel conduits. After the stent accesses the treatment site, the stent is generally mechanically expanded and thus expanded in the vessel conduits by the aid of an inflatable balloon. Thereafter, the transporting device is retreated from the stent and removed from a patient. The stent as an implant exists in a conduit at the treatment site.